The second collection of Su Doku puzzles, the crossword without words, which is taking the puzzle world by storm. Literally translated, Su means number and doku means place.

Su Doku is a number grid consisting of 9 large squares each divided into 9 smaller squares. Between 3 and 4 numbers are already provided in each of the smaller squares. The point is to fill the grid so that every column, every row and every 3x3 box contains the digits 1 to 9.
This book contains over 100 unpublished puzzles with four levels of difficulty. There are more difficult and fiendishly difficult puzzles than easy and mild puzzles included. Since The Times started to publish Su Doku they have received an enormous number of enquiries about the puzzle and the availability of books.
Wayne Gould, 59, is the brains behind Su Doku. Now retired, he was a High Court judge in Hong Kong.